There are many circumstances in which non-quadrate (e.g., circular, oval, triangular, or polygonal shape) labels are utilized, being applied to surfaces. In the last few years there has been an increasing demand for linerless labels because of the environmental and other advantages associated with them. The use of non-quadrate linerless labels, per se, is shown in pending application Ser. No. 08/173,083, filed Dec. 27, 1993. According to the present invention, a particular string of non-quadrate linerless labels is provided, as well as a method of detaching the individual labels from the string, a method of separating the string from surrounding matrix material, a method of applying burst labels directly to the surfaces of moving items, and apparatus for practicing all of these methods.
According to one aspect of the present invention, a method of acting on individual non-quadrate linerless labels in a string of in-line non-quadrate linerless labels connected to the other by ties is provided. The method is practiced using a burster having a first pair of low speed rolls, and a second pair of high speed rolls with a stationary blade between the roller pairs. The method comprises the following steps: (a) Moving the string of non-quadrate linerless labels, in a first direction, to the first pair of rolls. (b) Feeding the labels, one at a time, in sequence from the low speed rolls to the high speed rolls so that a tie connecting two consecutive labels of the string is positioned between the pairs of rolls. (c) Acting on a leading string with the high-speed rolls to cause the string to be tensioned and the tie between the roll pairs to engage the stationary blade and burst. And, (d) discharging the leading label, burst from the string in step (c), from the high speed rolls.
The labels have a first face with adhesive release material and a second face with pressure sensitive adhesive. Step (c) is typically practiced by bringing the non-adhesive face into contact with the stationary blade. There is also preferably the further step of, except during tensioning as recited in step (c), guiding the labels from the first and second roll pairs by bringing the adhesive face into contact with a non-stick guiding surface.
Normally, the string of labels is originally connected to a surrounding matrix by ties, in which case there is the further step, prior to step (a), of (e) separating the leading labels from the matrix; and (f) continuously automatically pulling the matrix in a second direction, distinct from the first direction, while physically engaging the label string so that the labels are not pulled with the matrix but instead are fed to the first rollers as recited in steps (a) and (b) separated from the matrix. Step (f) is typically practiced by physically engaging the first face of the label string with a smooth, substantially stationary surface.
After the practice of step (d), there is a further step of bringing the detached leading linerless label second face into contact with a surface to which the adhesive adheres. This additional step may be practiced by pushing the first face in a third direction, substantially transverse to the first direction, until the second face engages the surface, or by engaging the first face with a rotatable element and rotating the rotatable element to assist in moving the label second face into contact with the surface, by substantially simultaneously moving the surface into engagement with the second face by using air blast nozzles, or the like.
There may also be the further step of sensing the presence of the leading label being discharged during the practice of step (d), and moving the surface toward the label in response to that sensing. The label string is typically pulled by the low speed roll to move into proper position. Also, typically, there is a speed differential of between 3:1 to 2:1 between the high speed and low speed rolls.
The invention also relates to a label assembly per se which consists of: A string of a plurality of non-quadrate linerless labels disposed in line with at least one tie about 0.018-03 inches in width connecting consecutive labels in the string together, each label having a first face with adhesive release material and a second face with pressure sensitive adhesive. The labels may be circular, with a single tie connecting each label to another consecutive label in a string, and the string labels may be in roll form.
The invention also relates to apparatus for bursting individual labels from a string of in-line labels connected by ties. The apparatus comprises the following elements: A pair of low speed rolls with a nip therebetween. A pair of high speed rolls, with a nip therebetween. The rolls mounted so that the nips are in an imaginary straight line, and the rolls are all rotatable about substantially parallel axes of rotation A non-stick surface mounted between the low and high speed rolls extending substantially along the imaginary straight line. And a stationary bursting blade mounted between the pairs of rolls above the non-stick surface. The non-stick surface is preferably a plasma coated surface. Sensors are also typically associated with the apparatus, including a sensor located downstream of the high speed rolls.
The invention also relates to apparatus for separating a string of in-line labels connected by ties from a surrounding matrix to which the labels are also connected by ties. The apparatus comprises the following elements: A conveyor mechanism for pulling the labels in a first direction. A stationary hold-down device for engaging the labels after separation from the matrix and holding the labels so that they do not travel with the matrix. A matrix take-up mechanism for moving the matrix in a second direction distinct from and intersecting the first direction. And, an abutment engaging the matrix and the string of labels where the first and second directions intersect. The abutment preferably comprises a first roller rotatable about an axis substantially perpendicular to the first direction, which may be driven but preferably is an idler roller. The matrix take-up preferably includes a powered second roller rotatable about an axis parallel to the first roller axis. The stationary hold-down device preferably comprises an arm of rigid, smooth material.
According to another aspect of the present invention, linerless label applying apparatus is provided. This apparatus comprises the following elements: A pair of rolls having a nip therebetween, the rolls rotatable about parallel axes, extending in a first dimension, and the rolls pulling a linerless label therebetween in a second direction substantially perpendicular to the first dimension. Label engaging means downstream of the rolls in the second direction for engaging a label as it moves through the nip. And, conveyor means for moving a surface into operative association with the label engaging means so that the label is applied to the surface. The label engaging means may comprise a reciprocating plunger, conveyor belt, vacuum cylinder, at least one gas blast nozzle, or a variety of other structures.
It is a primary object of the present invention to provide for the effective and simple detachment of non-quadrate linerless labels from a string, and the application of the detached labels to a moving surface, in an automatic manner. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.